Publication WO 91/19115 describes a disc brake with a self-activating adjustment device. The clamping device of this disc brake contains a cam lever, which can rotate around an axis parallel to the brake disc plane and works jointly by way of a cross tie rod with one or two adjusting spindles, against which a brake lining is supported. Both adjusting spindles are coupled by means of a toothed belt. Protruding into an opening in one adjusting spindle is a rotary drive, which can be driven by the cam lever and, during the engaging stroke, causes screwing motion of one adjusting spindle and thereby, by the toothed belt, also of the other adjusting spindle in the direction approaching the brake disc. The rotary drive contains a one-way coupling as well as a torque-limiting coupling, through which a screwing motion of the adjusting spindles is prevented during the firm braking stroke and the releasing stroke.
Publication EP 0 730 107 B1 describes a disc brake with a push rod, which extends parallel to the brake disc plane and which, upon activation of a clamping device while twisting a clamping element, presses a brake lining against the brake disc in the direction of the axis of a brake disc. The disc brake has an adjustment device with a one-way coupling and a friction clutch for self-activating, abrasion-dependent adjusting of the free play between the brake lining and the brake disc, so that the entire adjustment device is coupled with the push rod in such a way that, upon braking, it follows its motion in the direction of the brake disc axis.
It is the object of the present invention to design a disc brake with simple means in such a way that a safe-functioning adjustment is ensured.